public class Example4_5 {
  public static void main(String args[]){
    Rect ractangle = new Rect();
    ractangle.width=109.87;
    ractangle.height=25.18;
    double area=ractangle.getArea();
    System.out.println("矩形的面积："+area);
    Lader lader=new Lader();
    lader.above=10.798;
    lader.above=156.65;
    lader.height=18.12;
    area=lader.getArea();
    System.out.println("矩形的面积："+area);
  }
}
